Separator



T. J. STURTEVANT, SEPARATOR. APPLICATION FILED OCT. I8. 1917.

1,353,547, PatentedSept. 21, 1920.

3 SHEETS-SHEET I alien/5703 /lakawney.

T. J. STURTEVANT.

SEPARATOR- APPLICATION FILED OCT. 18,1917- 7 I 1,353,547., Patented Sept. 21, 1920. a 3 swears-sum 2..

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SEPARATOR.

APPLICATION FILED 0CT.18| 1917.

PatentedSep 3 SHEETSSHEET Q v \V n tar ASSIGNMENTS,

CORPORATION OF MASSACHUSETTS.

T0 STURTEVANT MILL CGMPANY, OE BOSTON, MASSACHUSETTS, A

SEPARATOR.

fi m t n V Patented Sept. 21, 1920.

Application filed October 18, '1917. Serial No. 197,330.

To all whom it may concern:

Be it known that l, THOMAS J. STURTE- vaxr, a citizen of the Unlted State of Massachusetts, have inventedan Improvement in Separators, of which the following description,in connection with the accompanying drawings, isa specification, like characters on the driwvingsrepre-. senting like parts. i

The invention hereinafter described. relates to separators for grading materials, and more particularly to an improved screen therefor. w i

These separators usually comprise a casing having afeedbox at the-top thereof whichdelivers thematerialtobe graded to the upper surface of an inclined, vibrated screen in the casing. The liner material passes through the screen, and the coarser material flows along the screen,.the former. being delivered through one outlet and the latter being delivered through another outlet in the casing, s

In order to, produce etlicient grading of the material, it is essential thatthe screen clothing should be stretchedtightly on its su port. Sometimes the screen clothing is adjustably connected by'bolts directly .to the casing of the separator, and sometimes the clothing is stretched ona frame-mounted within the separator.)Heretofore, the devices employed tostretch the clothing have been applied to the margin; of theclothing in such a manner that the stretchin thereof increasedthe perimeter of the, clothing or frame, and thus onlya limited stretching of the clothing could-beobtained. One ofthe objects of the present invention is to provide simple and effective means whereby the screen can be stretched as required without increasing the perimeter thereof.

The vibration of the clothing and the weight of the material the'reontends to stretch certain portionsthereof more than others. Another object of theyinvention is to provide means whereby the clothing may be readily stretched to bagging thereof. i

A frame has been used to support the. clothing having cross bars tending to spread the side bars of the frame to stretch the clothing, as shown in Letters Patent of T.-

eliminate any local States, resid ing at Wellesley, county of Norfolk, and

L. Sturtevant, No. 1,125,762, dated January 19,1915, but the construction is such that there is no provision for the desirable application of the vibrating means to the screen within the boundaries of the frame. Another .object of the invention is to pro.- vide a frame having resilientbars and one or more resilient crossbars or members. which will tend to stretch the clothing,but will permit the desirable application of the vibrating means to the "screen within the boundaries thereof, and without interfering with the stretching of the clothing or obstruc ing the free flow of the material to be graded along-the screen'. V i 3 *TWhere pins have-been used 1to"trans'm it' blows from hammeridevices'to thescreen clothing, they have been applied'directlyto the clothing at distributed'points thereon, so that. the areas of the clothing adjacent said pins have experienced greater stretch ing and bagging than portions more remote from said pins.- The cross bar or bars may desirably'serve to distributethe blows from the pinstotthe clothing and eliminatelocal distortion of the clothing therefrom. Y

The character of the inventionmay be bestunderstood by reference to the following description of one good form thereof shown in the accompanying drawings, wherein: e i v I Figure .1 is azvertical section through separator illustrating the. invention; Figf 2 is a transverse section taken on line 2-2 of Fig.1; Fig. 3 on an enlarged scale is a planv of the screen; 1

.Fig. 4 is a plan of a portion of'a' bridge bar and a side bar of the screen showing the V meansconnectingthem, y I

i Fig. 5 is an end View of the construction shown in Fig. 4;

l ig. ()is' a vertical section taken on line 6- 6of'Fig. 4:; i

1 Fig. 7, on an enlarged scale is a-sectional detail showing the relation. of one ofthe:

Fig. 11 is a section taken on line 11-11 of Fig. 10.

' Referring to the drawings,-the separator shown therein as an exemplification of the invention, comprises a frame 1 (Fig. 1)" having a main frame, in the present instance, in the form of an inclined casing mounted thereon provided with a bottom 3, side walls 5, and a cover 7 with its upper end connected by a hinge 9 with the casing, and its lower end adapted to rest upon a transverse member 11 adjacent the lower end of the casing.

Ii trough 13 at the top of the casing contains a screw conveyer 15 adapted to feed the material to be g ;raded along the trough over a feed board 17, and deliver the same to a screen mounted within the casing.

This screen, in the present instance, of the invention, comprises a frame having longitudinal side members conveniently in the form of angle bars 19 (Fig. 3), and end 7 members conveniently in the form of fiat bars 21 having upturned ends 22 riveted or otherwise secured to the inner faces of the upper flanges of the side bars. Screen clothing 23 or other suitable screening material may be stretched on and riveted or otherwise secured to said frame.

The side bars of the frame may be sufficiently light and of a resilience such that they may be flexed inward between their points of connection with the end bars when the screen clothing is secured thereto. These bars will then tend to straighten and automatically stretch and maintain the clothing properly ten'sioned. One or more transverse members m-ay be provided, in the present instance, in the form of channel bridge bars-25 connected to the side bars by plates 27 (Figs. 4%, 5 and 6), conveniently triangular in shape, having enos 29 bent inward and riveted or otherwise secured to the under faces of the channel bars. The ends 31 of the depending flanges of the channel bars may engage the inner faces of said plates and contribute to the strength of the con struction. V

The bars and the plates have an inherent resiliency such that they tend to thrust outward or straighten the side bars, and thus do not detract from the tensioning effect of the side bars, but on the contrary, contribute to this effect. The bridge bars are spaced above the screen clothing a sufiicient distance to allow flow of the material to be graded beneath them without obstruction thereto. Said bars may not only serve to tend to straighten the side bars of the frame and stretch the screen clothing, but may also serve to transmit and distribute the blows of the hammer vibrating means thereto as hereinafter described.

Next will be described the means for stretching the screen clothing to eliminate local bagging or distortion thereof, and-for stretching the clothing without increasing the perimeter thereof. This means, in the present instance of the invention, comprises a stretching member in the form of a U- shaped bar 33, preferably extending the length of the screen, and having its ends superposed on and riveted to the end members 21 of the frame. The legs 35 (Fig. 7') of said member may be bent to present feet 37 which maybe riveted or otherwise secured to portions of the screen clothing. In the form of the invention shown, these feet are secured to the screen clothing adjacent the longitudinal center thereof. The inherent-resilience of the stretching member preferably tends to draw the feet thereof toward one another, and thereby continuously tends to stretch the screen clothing. Said member may be provided with adjustable means for controlling the stretching of the screen clothing, and for limiting the outward movement of the feet thereof. In the present irstance of the invention, this means comprises a series of bolts 39 (Figs. 1 and 7) entered through registering holes in the legs of said member. Thenuts 41 of the bolts may have flat faces thereof engaging one of the feet of the member to prevent rotation thereof, and the heads of the bolts may be formed to receive a screw driver for adjusting the same. Split spring washers 43 of usual construction may be confined be tween the heads of the bolts and the outer face of one of the legs of said member, and serve to permit turning of the screws in one direction and lock the same against turning in the opposite direction.

The stretching device for the screen may be located within the boundaries of the frame and stretch the screen clothin without increasing the perimeter of the frame. As a result, the original shape and size of the frame are maintained.

If fine mesh, light screen clothing is user, it will readily flex and pucker as at 45 (Fig. 7 between the feet of the stretching bar, where they are drawn toward one another, but-if coarse, heavy screen clothing is used, it would be divided intoseparate sections having their inner margins secured to the feet of the stretching member.

The stretching bar may be laterally flexible, so that portions-of the legs thereof may be drawn together to eliminate local bagging of the screen clothing. To accomplish this, the bolt or bolts connecting said legs adjacent the distorted portion of the clothing may be tightened, thereby locally flexing the legs of'the bar to increase the tension on the distorted portion. The bolts are readily accessible and'ea's'ily adjusted, so that all local bagging can be prevented. This means for local adjustment desirably cooperates with.

the 'tensioning side bars and bridge bars to maintain the clothing always properly stretched and in condition to produce most efficient screening effect.

Next will be described the means for imparting blows to the bridge bars to vibrate the screen. In the present instance of the invention, this means comprises pins 4E7 (Fig. 1) having lower ends adapted to rest upon bearing plates 49 secured to the tops of the channel bars. The upper ends of said pins project through holes in the casing cover, and receive blows from hammer devices comprising strikers 51 having ends pivotally connected to rotors conveniently in the form of hubs 53 fast on a shaft 55 journaled in hearings in brackets 57 mounted on the cover.- Spring members or strips 59 may have ends mounted on and secured to brackets 61 on the cover, and have free ends projecting over the upper ends of said pins to receive the blows of the strikers, protecting the ends of said pins from wear, and relieving said pins from the weight of the strikers after imparting their blows thereto substantially as described in my copending application, Serial No. 192578, filed September 21, 1917.

The flanges of the channel bars preferably engage the upper edge of the stretching bar, referred to, and the blows imparted to the pins are transmitted to the screen clothing by the channel bars directly to the side bars of the frame and through said stretching member to the end bars of said frame, thereby desirably distributing the vibratory effect of said blows to the screen clothing through said frame and stretching member. The construction is such that the pins are not applied directly to the screen clothing, and as a result, local stretching and bagging of the screen clothing. by the pins is prevented.

The channel bars serve not only to desirably distribute the vibration to the screen, but also prevent the pins from projecting to the screen in the path of the material flowing down along the upper surface of the screen. As a consequence, the available screening area is increased. The bridge bars may also serve ashandles whereby the screen may be conveniently grasped for the purpose of insertion of the same into the casing, and removal of the same therefrom.

The screen may be supported in the easing on the upper portions of curved leaf springs 63 (Figs. 1 and 2) secured on Z- bars 65 mounted on thebottom of the easing adjacent the side walls thereof. To guide the screen into position on said leaf springs, prevent injury to the screen cloth ing from said springs, and limit downward and lateral movement of the screen on said springs, stop plates 67 (Figs. 10 and 11) may be riveted or otherwise secured to the side bars of the frame and have portions projecting inward beneath the screen clothing. Rims depend from said plates and have inclined portions 69 which may engage the inner edges of the springs and guide the screen into position with its side bars above the springs. End portions 71 of said rims then engage the free ends of the springs and limit the downward movement of the screen. To prevent the material to be graded from escaping over the sides of thescreen, shield plates 73 (Figs. 1 and 2) may be secured to the outer faces of the upstandingflanges of the side bars of the screen frame, and said plates may overlap similar plates 7 7 secured to and depending from the .under face of the cover. I By my invention, a screen is provided which is simple and strong in construction. The screen clothing thereof is readily maintained in efiicient tension, and the blows of the vibrating devices are so distributed to V the screen that distortion and wear of the screen clothing are reduced to a minimum.

It will be understood that the invention is not limited to the specific embodiment shown, but that various deviations maybe made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is: V

1. A screen for separators, comprising a frame having side and end members, screen clothing secured to said side members, a member extending along said clothing intermediate and substantially parallel to the side members of said frame and secured to the end members of said frame, and means cooperating with said intermediate member to stretch the clothing, said intermediate member and stretching means cooperating therewith located in their entirety above said clothing.

2. A screen frame, screen clothing. secured to said frame, a channel above said clothing having flanges projecting downward toward said clothing to prevent the material to be graded from entering and choking said channel, and means cooperating with said channel for for separators, comprising a stretching said clothing with a pull thereon coiiperating with said members relatively to flex said members to take up and eliminate any local sagging of the clothing.

5. In a separator for'gradingmaterials, the combination of an inclined screen comprising a frame, screen clothing secured thereto, a device extending along said clothing intermediate and substantially parallel toopposed sides of said frame for stretching'said clothing with a pull in a direction inward from said sides, and means operating through said stretching device for vibrating the clothing and promoting the passage of materials to be graded therethrough.

6. A separator for grading materials hav ing, in combination, an inclined screen comprising a frame, screen clothing secured thereto, a channel above said clothing and secured to said frame, means cooperating. with said channel to stretch the clothing; and means to vibrate said channel and clothing.

7. A separator for grading materials having, in combination, a screen comprising a frame, screen clothing secured thereto, a

channel above said clothing, means cooperating with said channel to stretch the cloth 111g; and means lncluding hammers and pins receiving blows from said hammers and operating through said channel to vibrate said clothing,

8. In a separator, the combination of a main frame or casing; a screen frame therein comprising opposed side members, transverse members to hold'said side members in spaced relation, and a stiiily resilient bridge bar provided with downwardly extending ends'rigidly secured to said side members; screen clothing stretched on said screen frame and spaced a substantial distance beneath said bridge bar, hammer means mounted on the main frame or casing, a cover positioned between said screen Irame and said hammer means, and a pin having an end projecting through said cover to receive blows from said hammer means and an end resting on said bridge bar to vibrate said bar, frame and clothing.

9. In a separator, the combination of a main frame or casing, spring supporting means therein, a screen frame mounted on said spring supporting means and comprising opposed side members, and a sti'llly resilient bridge bar having ends secured to said side members, screen clothing stretched on said screen frame and spaced a substantial distance beneath said bridge bar, a pin resting on said bridge bar above the clothing, and hammer means mounted on said main frame or casing to strike blows on said pin to vibrate said clothing 10. In a separator, the combination of a main frame or casing, an inclined frame mounted therein com-prising opposed side members and a vibratory bridge bar secured to said side members, screen clothing for grading materials stretched on said inclined frame a substantial distance beneath said bridge bar, that the latter may vibrate without interference with materials flowing along said clothing, and hammer means mounted'on said main frame or casing for impartingblows to said bridge bar at a point a substantial distance in from the ends thereof to vibrate said clothing through the frame therefor.

11. A screen for separators, comprising a frame, screen clothing secured thereto, a bridge member extending above and transversely'of the screen clothing and including a channel bar having flanges projecting therefrom, and plates or equivalent elements connecting said bar with opposed sides of said frame and adapted to engage the ends of said flanges to limit fleXion of saidplates or elements relatively to said channel.

12. A separator for grading materials having, in combination, ascreen comprising a frame, screen clothing secured thereto, a

stretching bar having means for stretching the clothing with a pull away from opposed sic es of said frame, a bridge bar extending transversely of said frame and stretching bar and secured to said opposed sides of said frame; and means to impart vibrations to said bridge bar and stretching bar to vibrate said clothing.

In testimony whereof, I have signed my name to this specification.

THOMAS J. STURTEVANT. 

